Call that script from /etc/rc.local (commands from this script are launched on each boot). Open file /etc/rc.local:

sudo gedit /etc/rc.local

before exit 0 line, put the following line:

/usr/local/bin/detect-gl

Your whole file should look more or less like this:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
/usr/local/bin/detect-gl
exit 0

This script will make sure the proper GL library is used for both graphics cards (Mesa lib for Intel, nVidia lib for nVidia card).

Fixing nVidia backlight issues

This is the most elegant solution I could think of. As the brightness settings almost work (when you press the Fn-F5, Fn-F6 keys, the notification appears and the bar shows you the backlight changes) we'll use D-Bus to listen for backlight change signal to set the backlight using nvclock command.

Poor 3D performance

When running Unity all the 3D games have poor performance. I found the easiest workaround is to log in into Classic Ubuntu (with no effects) desktop, which gives you standard GNOME with no compiz and nice 3D performance for launched apps.

Dual-screen issues

I'm using a dual-screen setup (laptop's LCD + external monitor connected via VGA port). The current version of Ubuntu has multiple issues with this, especially when aligning the screens in vertical (laptop's screen being the bottom one, big LCD the top one). The "dock" or "launcher" if you wish appears on the wrong screen (the small laptop instead of on the big screen). To fix this do this:

xrandr --output VGA1 --primary

Log out and in again after doing this. Launcher is on top screen now :-).

I found another irritating bug: when you plug in a big external monitor into the VGA port, the desktop automatically expands to both monitor (not a bug yet), but on one or both of them, some area is black, so you can't see the menus and windows. Logging out and in is also a workaround for this.

When you log in with an external monitor connected, the desktop is strangely stretched and has some artifacts. Interestingly taping Super button (to show the Ubuntu Dash) and Escape (to hide it) refreshes the screen and it looks OK then.

It's hard to put some windows on the bottom screen (your mouse pointer stops on the bottom of the top screen while dragging). You can move the windows even further down using Alt and dragging by window content (and not the title bar).

Once a window is on the bottom screen, trying to resize it crashes the application and it disappears… The workaround is to resize by holding Alt key and drag with middle mouse button.

Other issues

When using Intel graphics card and Unity, Adobe Flash movies (YouTube for example) shows some artifacts. From time to time they also crash the whole X session (I'm not sure why).

A few weeks after testing Ubuntu 11.04 beta 1 which brought me a bit of disappointment, I decided to test the recently released final version of this most popular Linux distribution.

As I had no more CDs or DVDs, I decided to try booting the distribution from USB drive that I assembled from microSDHC card reader and a microSD 4GB card that I got with my Android phone using standard Ubuntu tool called "Boot disk assistant", which burns CD ISO file onto a USB drive in a way that it becomes bootable equivalent of the CD with additional option to save the modifications you make to the Live system on the disk itself, so that it becomes more or less persistent.

LiveUSB creation

First I decided to use that option and let the program use about 3 GB for the overlay file. This made the program busy for about a half an hour, the card reader (actually writer) got warm, and the result was the USB was not that bootable.

A day after that attempt I decided to give it a try without the persistence and it worked this time. The problem came when I tried to "Try Ubuntu" (in opposite to "Install Ubuntu"). The graphic mode quited and I got nothing in return. I tried multiple things to do in text mode, rebooted a few times and after that it appeared that the graphic mode re-run after about a minute. The CPU was completely idle in this time as was the disk, so this wasn't reasonable thing.

Anyways it appeared the release was much more stable than the beta version I tested and it kind of even worked. I found a few concepts useful and cool, so I decided to put the system on my disk to give it a serious try.

Having it on disk

Automatically detecting an external monitor was the biggest positive surprise for me. This never worked in Ubuntu till now. The downside is the graphics got crazy and displayed desktop in not really usable chunks, but I moved some windows around and it got fixed.

nVidia troubles

Then I tried booting with nVidia graphics card enabled (I have a dual-graphics Sony Vaio laptop) to see if the drivers would automatically install. Ubuntu first booted into classic Ubuntu mode (no fancy Unity desktop shell) but it was usable. I navigated to System » Administration » Additional Drivers and chose the recommended proprietary nVidia drivers to install. They got installed and I was asked to reboot the computer so I did.

After the reboot graphic mode was not working and so didn't the text mode. I rebooted with Intel graphics card to discover that installing the nVidia drivers broke Intel drivers which made me without Unity desktop shell even on previously working Intel card. Since I knew what to do to "fix" nVidia I did this — I blacklisted the nouveau module and also a bunch of tpm modules that prevented from proper resume after suspend in previous version of Ubuntu. And rebooted with nVidia card chosen.

This time Xorg went up, the Unity showed up and everything was more or less OK. After removing nVidia drivers (apt-get remove nvidia-current) Intel got working Unity back. But I wanted to have Unity working on both graphics card without constant installing and uninstalling nVidia drivers and I figured out how to do it.

This code checks whether current GL implementation is nVidia (valid for nVidia card) or Mesa (valid for Intel card), then checks current card by examining the output of lspci command and uses certain update-alternatives lines followed by ldconfig to update the GL implementations. killall Xorg kills the X server which is brought back by login manager with GL library updated.

This is a dirty hack but it works just well for me and made both graphic cards working with no additional work.

Glitches/Summary

Ubuntu seems very stable now, but X server crashed a few times (especially loading Flash videos from Vimeo in Firefox). There are some problems in multi-monitor configurations, like no way to move the window to bottom monitor (if they are aligned vertically) by dragging its top bar (moving with Alt works). The windows on bottom monitor are not maximized properly (they are maximized on the top monitor instead) and they can't be resized by dragging the resize handles (but resizing with Alt+middle mouse button works).

There were some other small random issues, either not really relevant or easily fixable, but overall it seems a very good beta release. But wait. This is no beta, but final release. In this case it's not good. It's OK for a Linux user like me, but it definitely should not be released for regular users. Shame on you Canonical. They promised they release in April, but they should have release another beta release, do a serious testing (what I did was anything but unusual), fix the remaining bugs and then release the final version.